Abstract

To describe changes in haemoglobin over time and to determine the joint prognostic value of the current haemoglobin, CD4 lymphocyte count and viral load among patients from across Europe.

Patients:

The analysis included 6725 patients from EuroSIDA, an observational, prospective cohort of patients with HIV from across Europe.

Methods:

Normal haemoglobin was defined as haemoglobin greater than 14g/dl for men and 12g/dl for women; mild anaemia was 8-14g/dl for men and 8-12g/dl for women; severe anaemia was defined as less than 8g/dl for both males and females. Linear regression techniques were used to estimate the annual change in haemoglobin; standard survival techniques were used to describe disease progression and risk of death.

Results:

At recruitment to the study, 40.4% had normal levels of haemoglobin, 58.2% had mild anaemia and 1.4% had severe anaemia. At 12 months after recruitment, the proportion of patients estimated to have died was 3.1% [95% confidence interval (CI) 2.3-3.9] for patients without anaemia, 15.9% for patients with mild anaemia (95% CI 14.5-17.2) and 40.8% for patients with severe anaemia (95% CI 27.9-53.6; P<0.0001). In a multivariate, time-updated Cox proportional hazards model, adjusted for demographic factors, AIDS status and each antiretroviral treatment as time-dependent covariates, a 1g/dl decrease in the latest haemoglobin level increased the hazard of death by 57% [relative hazard (RH) 1.57; 95% CI 1.41-1.75; P<0.0001], a 50% drop in the most recent CD4 lymphocyte count increased the hazard by 51% (RH 1.51; 95% CI 1.35-1.70; P<0.0001) and a log increase in the latest viral load increased the hazard by 37% (RH 1.37; 95% CI 1.15-1.63; P=0.0005).

Conclusions:

Severe anaemia occurred infrequently among these patients but was associated with a much faster rate of disease progression. Among patients with similar CD4 lymphocyte counts and viral load, the latest value of haemoglobin was a strong independent prognostic marker for death.